Q: A friend told me that some common
houseplants like aloe and ivy are actually poisonous to animals. I have those
two, although my dog has never tried to eat them. Are they really poisonous? What
other houseplants are poisonous, and what happens if a pet eats them?

A: A surprising
number of houseplants are toxic in some ways to pets. Dogs and cats are
sensitive to more plant species than people.

The good news is
that most of the houseplants you'll find on "Poison Plant" lists aren't acutely
poisonous or deadly. The main problems are things like nausea, diarrhea,
vomiting, listlessness and sometimes irritation of the mouth, tongue, throat or
stomach from allergic reactions to the sap.

Very few plants are
actually deadly or serious threats. These include oleander, castor bean, yew,
Jerusalem cherry and mistletoe berries.

Ivy is a plant that
can cause vomiting, abdominal pain, excess salivation and diarrhea if eaten by
a pet.

Aloe can can cause
vomiting, depression, diarrhea, loss of appetite and tremors.

I've never been
able to figure out much of a pattern to what's toxic and what's not. Also, dogs
are sensitive to some things that cats aren't and vice versa. Easter lilies are
a serious threat to cats, for example, but dogs don't react.

The only way to
determine is to check each plant – one by one – and to research what its threat
is and to what animal.

The best source I
know of is the American Society for the Prevention of Cruelty to Animals' web
site. The ASPCA's site has a section that includes a detailed, plant-by-plant
list on both toxic ones and non-toxic ones.

The information
includes the threatening parts, the symptoms related to eating those parts, and
whether it affects dogs, cats and/or horses.